Photothermally Initiated Tandem Charge Transfer for Self-Sustained Reactive Oxygen Species Generation and Water Decontamination.

Photo-Fenton-like processes are green and sustainable technologies for wastewater purification; however, their practical application is commonly constrained by a narrow UV-light response, sluggish redox cycling, and severe performance attenuation in complex water matrices. Herein, we construct robust and pH-universal oxygen vacancy-rich TiO2-x@Bi2S3 quantum dot heterojunctions (TO-V@BS), which exhibit efficient full-spectrum light harvesting, stable self-sustaining charge transfer, and outstanding anti-interference performance under realistic water treatment conditions. The experiments and theoretical investigations reveal an integrated electron regulation network within TO-V@BS, where Bi2S3 serves as a photothermal generator and electron donor upon broad-spectrum irradiation while TiO2-x functions as a dynamic electron buffer through Ti3+/Ti4+ redox cycling to facilitate rapid electron transport. The introduction of a small amount of peroxydisulfate (PDS) further facilitates charge separation and electron utilization, enabling the construction of a coupled photothermally initiated reaction system with TO-V@BS. This synergistic configuration establishes a tandem charge transfer cascade to promote reactive oxygen species (ROS) generation, reaching 92.25% tetracycline (TC) degradation. Notably, TO-V@BS exhibit excellent long-term stability and sustained reactivity in the purification of real wastewater. This work provides a sustainable and feasible design of a photocatalyst for advanced environmental remediation.